Grading Flex Nibs

Finding a good flex pen is not easy. Good flex nibs are very difficult to identify. Pictures of “flexing” can be misleading. There are many out there claiming to sell a “wet noodle” because the nib has some decent line variation. Others call a nib “semi-flex” because it’s line variation isn’t massive. But it isn’t that simple. Unfortunately, there is no uniform, standard grading scale for flex nibs. I have too often been fooled by swirly lines and supposedly great flex. Thus, I grade flex nibs in attempt to give buyers an idea of EXACTLY what they are getting. I grade flex nibs in four categories: 1) ease of flex, 2) snap-back or responsiveness (how quickly a nib returns from broad to fine), 3) ink flow, and 4) line variation. Many people think flex means huge lines. But Super DOES NOT necessarily equal big. Super equals quality of flex (See samples below for more information).

Note: All the flex writing in the pictures is done on Rhodia paper so as not to give a distorted picture caused by the ink line swelling on absorbent paper. The measurements are not of the pen flexed to the max but of what I would consider the “safe zone.” Below is how I classify each level from semi-flex to wet noodle.

SEMI-FLEX: Decent line variation with significant pressure. Many vintage 14kt. nibs I would classify as “semi-flex.” Semi-flex is usually also not very responsive making great flex writing difficult. Many people claiming flex nibs really have a semi-flex or perhaps medium flex nib. Many others call semi-flex anything that doesn’t have almost wet noodle line variation. It’s confusing, I know.

MEDIUM-FLEX: Better line variation, but still with rather significant pressure. If you are familiar with a Noodlers flex pen, it to me would classify as medium flex. Sometimes flexibility comes more easily, but the nib does not spring back to it’s fine point as quickly making it more difficult to achieve good line variation in writing. Flow is also often not quite as good or inconsistent.

GOOD FLEX: Line variation comes with much more ease. Nib is more responsive and adjusts well between wide and fine lines. Some pretty good flex writing can be done with a good flex nib. But it will probably require a bit more care.

SUPER FLEX: Not a wet noodle, but line variation comes relatively easy with a super flex nib. It may or may not have greater line variation than a good flex, but it requires small pressure to adjust line size. It is also more responsive and quicker to move from the fine line (or extra fine) to double or triple bold and back to fine.

Wet Noodle: Flexing is so easy that it can almost feel like a paintbrush. A simple downstroke can easily widen out fairly significantly. Some can be so “flexy” that they are difficult to control and require a very light touch. Others flex with a bit more pressure at first and thus can be used as a daily writer. Wet Noodles are generally hard to find and rather expensive when you do. Unless of course you get lucky!



Now from the above shot, it is simply impossible to determine the quality of flex of each of these pens. The first is a Waterman 52, the second is a Wahl gold-filled, the third is a Waterman 12 PSF, and the fourth a Majestic. But still that doesn’t help. If you judge purely on line variation, then many would call these semi-flex pens because there is no line wider than 1.4mm. But this would be a terrible mistake in my judgement, as I hope the next picture makes clear.


Even though pictures don’t show the differences as dramatically as in person, you can still see the major disparity between the crispness of flex of the Super and Semi flex writing. If you go by line size, then the Waterman 12 PSF wins (Medium Flex). It has lines over 1.6mm. But the snap-back isn’t there, so the flexing is bit more sloppy. Super and Good look close, but the Wahl (Good Flex) required a lot more care and the nib was stiffer. In fact, the top line was written the fastest and with the least amount care. Super flex nibs make flexing feel natural. To classify all these as Semi flex or Moderate flex or some other categorization is just too generic. There are massive differences between the quality of these nibs. So again, Super DOES NOT equal BIG. Super equals QUALITY of flex.

Now what about the difference between a Super flex and a Wet Noodle? Well, the differences can be fairly dramatic as the next picture illustrates.

Waterman 12 Super-Flex compared to a Waterman 12 Wet Noodle


10 thoughts on “Grading Flex Nibs

  1. Thanks, super informative!
    Question: you demonstrate the Waterman #12 with Super Flex and a Wet Noodle – does this mean that when one buys a #12 Waterman, one’s not necessarily getting the same nib? Is there a lot of nib variation between different pens of the same model? (or did you fit different nibs on the same model for the purpose of this demo?)


    • That is correct. There is no guarantee of a good flex nib with any vintage pen. Waterman 12s do have a higher likelihood of flexibility than some other pens, but the degree of flex is quite varied. Waterman 12s were sold with the #2 Waterman nib, which is the same size used in many Waterman pens. And the #2 nib can be anything from rigid with no flex to paintbrush, wet noodle flex. The only way to truly know how much flexibility a nib has is to write with it.


    • Kat, yes there are XF-BBBB wet noodles. For me that would be 0.3-2.8mm. That’s just a massive range and extremely difficult to find, but they do exist. Though you can expect them to be very expensive due to their rareness.


    • Good question. I have only tried the FA nib on the 912. Originally, I was unimpressed, but after removing the baby’s bottom on the nib and modifying the feed, I got it to perform much better. Still, as it is I would only grade it as a “good flex” because the feed is still finicky. However, if the feed kept up well, I’d bump it up to a “super flex.” Mine is very soft but it lacks the spring and snap back of a higher quality “super flex” or “wet noodle.”


  2. Just wanted to compliment you on your knowledge and the clarity and quality of the information that you share. I’ve done a lot of research on flex nibs, and have not found any other site that is as lucid and as educational as yours. (Richard Binder might be a close second, but your writing samples and explained comparisons are first rate! The Fountain Pen community benefits greatly from the knowledge you share. Keep up the great work!


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